New apparatus for measuring radon adsorption on solid adsorbents

Hassan, Neguib M.; Hines, Anthony L.; Ghosh, Tushar K.; Loyalka, Sudarshan K.; Ketring, Alan R.

doi:10.1021/ie00057a024

Cited by 9 publications

(4 citation statements)

References 8 publications

(12 reference statements)

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“…The radon adsorption capacity of AC can be measured by the dynamic adsorption method [18] or the static adsorption method [19][20]. The static adsorption method was adopted in this study because of its simplicity and requirement of small amount of adsorption materials.…”

Section: Measurement Of the Radon Adsorption Capacitymentioning

confidence: 99%

Improving the Radon Adsorption Capacity of Activated Carbon by Liquid Nitrogen Modification

Deng

et al. 2023

J. Phys.: Conf. Ser.

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Radon is a naturally occurring radioactive inert gas that poses a significant threat to the human health. Coconut shell activated carbon has been verified to be the best radon adsorbing material, but its radon adsorption capacity still cannot meet the requirement of industrial applications. Activated carbon modification using liquid nitrogen is an effective method for improving the radon adsorption capacity, but it is necessary to determine the conditions for large-scale production. In this study, the influence of environmental temperature, container geometry, and amount of activated carbon and liquid nitrogen on the modification effect are examined. The results show that the activated carbon has the best modification effect when the container is placed in a water bath at 50 °C. The container geometry and activated carbon mass have a minor influence on the modification effect. Further, the radon adsorption capacity is increased by 36% when 6.5 L of liquid nitrogen is added to 1 kg of activated carbon. The characterization results reveal that the chemical structure and elemental content of the activated carbon do not change after modification, but the number of micropores is significantly increased, especially the micropores with a size of 0.5-0.6 nm, which is related to the radon adsorption capacity of the modified activated carbon. Overall, the liquid-nitrogen-based modification is a simple, environment-friendly, and low-cost method to improve the radon adsorption capacity of activated carbon, which can be used in the large-scale production of highly efficient radon adsorbents.

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Section: Measurement Of the Radon Adsorption Capacitymentioning

confidence: 99%

Improving the Radon Adsorption Capacity of Activated Carbon by Liquid Nitrogen Modification

Deng

et al. 2023

J. Phys.: Conf. Ser.

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“…A count time of at least 10 minutes was required to obtain a statistically significant count. A detailed description of the apparatus is given by Hassan et al (8).…”

Section: Apparatus and Proceduresmentioning

confidence: 99%

“…After each incremental pressure increase, 3.5 hours were allowed for radon and its daughters that had been adsorbed on the solid to reach radioactive equilibrium. It should be noted that radioactive equilibrium is different from physical adsorption equilib- rium which is established between the radon in the gas and on the adsorbent in approximately 15 minutes (8). Once radioactive equilibrium was reached, the gas-phase and solid-phase counts were obtained simultaneously.…”

Section: Apparatus and Proceduresmentioning

confidence: 99%

“…5 and 6. The parameters can be expressed in terms of percent relative humidity (%RH) as kl = 2.25 x lo-" -1.49 x lo-'' X %RH (7 ) and k2 = 2.77 + 2.01 x lo-'' %RH (8) The amount of radon adsorbed on BPL activated carbon at 298 K and at any relative humidity may then be expressed as in the figure are experimental data for different relative humidities, and the solid lines represent the predicted curves. The equilibrium isotherms of radon, such as the ones shown above, can be used for measuring radon concentrations in homes, provided accurate isotherm data are available for the activated carbon.…”

Section: Correlation Of Equilibrium Datamentioning

confidence: 99%

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Adsorption of Radon from a Humid Atmosphere on Activated Carbon

Hassan¹,

Ghosh²,

Hines³

et al. 1992

Separation Science and Technology

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Temperature and relative humidity can influence the adsorption capacity of radon on activated carbon to a great extent, depending on the physical properties of the carbon. Experiments were carried out to measure the radon uptake by an activated carbon in the presence of water vapor in a specially designed adsorption apparatus. The radon concentrations in the gas and solid phases were measured simultaneously once the adsorption equilibrium and the radioactive equilibrium between the radon daughter products were reached. The experiments in the presence of water vapor were carried out using two approaches. In one case the activated carbon was preequilibrated with water vapor prior to exposing it to radon. In the other case the carbon was exposed to a mixture of water vapor and radon. The uptake capacity for radon decreased substantially when both components were introduced together compared to when carbon was preequilibrated with water.

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